INFO: task kworker/u4:3:840 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:3 state:D stack:21352 pid: 840 ppid: 2 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
__mutex_lock_common+0xc71/0x2390 kernel/locking/mutex.c:669
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28
hfsplus_cat_write_inode+0x1e3/0x820 fs/hfsplus/inode.c:588
write_inode fs/fs-writeback.c:1505 [inline]
__writeback_single_inode+0x6c3/0xda0 fs/fs-writeback.c:1715
writeback_sb_inodes+0x9fe/0x1610 fs/fs-writeback.c:1940
__writeback_inodes_wb+0x12a/0x3f0 fs/fs-writeback.c:2011
wb_writeback+0x455/0xb90 fs/fs-writeback.c:2116
wb_check_background_flush fs/fs-writeback.c:2182 [inline]
wb_do_writeback fs/fs-writeback.c:2270 [inline]
wb_workfn+0xb47/0xe60 fs/fs-writeback.c:2298
process_one_work+0x863/0x1000 kernel/workqueue.c:2310
worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
INFO: task kworker/0:5:4217 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:5 state:D stack:25856 pid: 4217 ppid: 2 flags:0x00004000
Workqueue: events_long delayed_sync_fs
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
__mutex_lock_common+0xc71/0x2390 kernel/locking/mutex.c:669
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
hfsplus_sync_fs+0x262/0x770 fs/hfsplus/super.c:223
delayed_sync_fs+0x94/0xe0 fs/hfsplus/super.c:271
process_one_work+0x863/0x1000 kernel/workqueue.c:2310
worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
Showing all locks held in the system:
1 lock held by khungtaskd/27:
#0: ffffffff8c11c720 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
4 locks held by kworker/u4:3/840:
#0: ffff888141b88138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1: ffffc9000394fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
#2: ffff888023b440e0 (&type->s_umount_key#51){.+.+}-{3:3}
, at: trylock_super+0x1c/0xf0 fs/super.c:418
#3: ffff88807d95c0b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28
2 locks held by getty/3945:
#0: ffff88814d431098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1: ffffc900026562e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158
3 locks held by kworker/0:5/4217:
#0: ffff888016871138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1: ffffc90002dffd00 ((work_completion)(&(&sbi->sync_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
#2: ffff88814cfba998 (&sbi->vh_mutex){+.+.}-{3:3}, at: hfsplus_sync_fs+0x262/0x770 fs/hfsplus/super.c:223
9 locks held by syz-executor.0/4592:
1 lock held by udevd/4888:
4 locks held by syz-executor.0/7651:
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
watchdog+0xe0f/0xe50 kernel/hung_task.c:369
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4592 Comm: syz-executor.0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:memset_erms+0xb/0x10 arch/x86/lib/memset_64.S:65
Code: 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 f3 aa <4c> 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01 01 01
RSP: 0018:ffffc90002eceff8 EFLAGS: 00000202
RAX: 00000000ffff0a00 RBX: ffff0a0000000509 RCX: 0000000000000000
RDX: 0000000000000018 RSI: 0000000000000000 RDI: ffffc90002ecf098
RBP: ffffc90002ecf120 R08: dffffc0000000000 R09: ffffc90002ecf080
R10: fffff520005d9e13 R11: 1ffff920005d9e10 R12: ffff0a0000000509
R13: 00000000000000ed R14: ffffc90002ecf401 R15: ffff0a0000000509
FS: 00007fe1769996c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f54e2713c00 CR3: 00000000249f6000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
number+0x277/0xf70 lib/vsprintf.c:457
vsnprintf+0x10fe/0x1a00 lib/vsprintf.c:2877
sprintf+0xd6/0x120 lib/vsprintf.c:3013
print_time kernel/printk/printk.c:1274 [inline]
info_print_prefix+0x152/0x300 kernel/printk/printk.c:1300
record_print_text kernel/printk/printk.c:1349 [inline]
console_unlock+0x7f5/0x1200 kernel/printk/printk.c:2725
vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274
_printk+0xcc/0x110 kernel/printk/printk.c:2299
hfsplus_bnode_read_u16 fs/hfsplus/bnode.c:62 [inline]
hfsplus_bnode_dump+0x30b/0x430 fs/hfsplus/bnode.c:369
hfsplus_brec_remove+0x476/0x540 fs/hfsplus/brec.c:229
__hfsplus_delete_attr+0x1d1/0x360 fs/hfsplus/attributes.c:299
hfsplus_delete_all_attrs+0x240/0x3a0 fs/hfsplus/attributes.c:378
hfsplus_delete_cat+0x94a/0xd20 fs/hfsplus/catalog.c:425
hfsplus_unlink+0x33c/0x760 fs/hfsplus/dir.c:385
vfs_unlink+0x385/0x600 fs/namei.c:4288
do_unlinkat+0x382/0x6f0 fs/namei.c:4356
__do_sys_unlink fs/namei.c:4404 [inline]
__se_sys_unlink fs/namei.c:4402 [inline]
__x64_sys_unlink+0x45/0x50 fs/namei.c:4402
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fe177617b29
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe1769990c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 00007fe177736f80 RCX: 00007fe177617b29
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000000
RBP: 00007fe17766347a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fe177736f80 R15: 00007ffeac6723e8